Work indexing means for disc grinders



July 4, 1961 J. A. BENKOVICH ET AL 2,990,659

WORK INDEXING MEANS FOR DISC GRINDER-S Filed Jan. 16, 1958 6Sheets-Sheet 1 VIIL.

Ju y 4, 196 J. A. BENKOVICH ETAL 5 5 WORK 'INDEXING MEANS FOR DISCGRINDERS Filed Jan. 16, 1958 6 Sheets-Sheet 2 INVENTOR N A. .BE/VKOWCH h\TTORNEY July 4, 1961 J. A. BENKOVICH ETAL 2,990,659

WORK INDEXING MEANS FOR DISC GRINDERS 6 Sheets-Sheet 3 Filed Jan. 16,l958 July 4, 1961 J. A. BENKOVICH ETAL WORK INDEXING MEANS FOR DISCGRINDERS 6 Sheets-Sheet 4 Filed Jan. 16, 1958 INVENTOR JOHN ,4.a:wxowc//J/MM/E L. WH/T'TINGTDN BY RALPH EZPRICE ATTORNEY July 4, 1961 J. A.BENKOVICH ETAL WORK INDEXING MEANS FOR DISC GRINDERS 6 Sheets-Sheet 5Filed Jan. 16, 1958 INVENTOR JOHN A-BENKOWCH J/MMIE L.WHI7TIN6TON BYRALPH 5. PRICE /fi7/ h ATTOR EY y 1961 J. A. BENKOVICH ETAL 2,990,659

WORK INDEXINGMEANS FOR DISC GRINDERS Filed Jan. 16,1958 6 Sheets-Sheet 6INVENTOR JOHN A. BEN/(D VIC/1' d/MM/E Am /771N670 ATTORNEY AM PH P ICEUnited States Patent O 2,990,659 WORK INDEXING MEANS FOR DISC GRINDERSJohn A. Benkovich and Jimmie L. Whittington, Beloit, Wis., and Ralph E.Price, Waynesboro, Pa., assignors to Gardner Machine Company, Beloit,Wis.

Filed Jan. 16, 1958, Ser. No. 709,408 7 Claims. (Cl. 51118) Thisinvention relates to surface grinders of the type known as disc grindersfor grinding opposed parallel sides of workpieces.

In order to grind workpieces having two or more sets of parallel sidesor ends, it is necessary to index the workpieces to change from theposition for grinding one pair of parallel sides or ends, to positionfor grinding another pair of parallel sides or ends. The usual way ofeffecting such indexing is for the operator to remove the piece from thecarrier after the first pair of parallel sides have been ground, turnthe work 90 and replace it in the carrier in position to grind thesecond pair of parallel sides. It is possible to provide automaticindexing where the work holder in the carrier may be indexed. However,there are a number of serious disadvantages involved in indexing in thismanner.

It is therefore an object of this invention to provide means operable intimed relation to the movement of the carrier to remove a workpiece fromthe carrier after one pair of opposed parallel sides has been ground,turning the workpiece to a position to present the next pair of opposedparallel sides for grinding and return the workpiece in this position tothe carrier.

1 'Another object is to provide means operable by engagement with amoving workpiece to remove a subsequent workpiece from the work holder.

Another object is to provide means whereby one workpiece is transferredfrom the carrier to the indexer, said means being eifective alternatelyto transfer an indexed workpiece to the carrier.

Another object is to provide means for discharging alternate workpiecesfrom the carrier and for retaining other alternate workpieces in saidcarrier.

FIGURE 1 is a partial end elevation showing the relation between thework carrier and the indexer.

FIGURE 2 is a section on the line A-A of FIGURE 1 showing the means foreffecting the index movement. FIGURE 3 is an enlarged partial endelevation showing the work transfer fingers in one position.

FIGURE 4 is an enlarged partial end elevation showing the work transferfingers in another position.

FIGURE 5 is an end elevation showing the means for driving the carrierand the indexer.

FIGURE 6 is a partial end elevation showing the location of certainlimit switches which co-operate with the carrier.

FIGURE 7 is a partial plan view showing the mounting of one of saidlimit switches.

FIGURE 8 is a combination front elevation and e1ectrical diagram showingthe relation between said limit switches and the parts which theycontrol.

FIGURE 9 is a digaramatic plan view showing the positions of the gagecontacts.

Numeral 10 indicates a work carrier for a double disc grinding machinehaving opposed, rotatable abrasive discs 17 and 18. Work carrier 10 hasdistributed about its periphery an even number of work holding fixtures11, each having a V-notch 12 for receiving a workpiece, such as auniversal joint spider 13. Workpieces 13 are held in fixtures 11 by belt.14 carried on pulleys 15 and 16at the upper position, passing over theworkpieces on carrier '10 to the point of discharge at the lower end ofcarrier 10 from which they pass over another set of pulleys (not*shown), but identical with pulleys 15 and 16.

7 2,990,659 Patented July 4, 1961 Means for indexing said universaljoint spider '13 to present a second pair of parallel faces for grindingcon sists of a rotatable member 20 peripherally opposed to work carrier10 and rotated synchronously with work carrier 10 by means which will bedescribed later. Said indexing member 20 consists of a series of workholding fixtures, un-even in number, peripherally spaced about indexingmember 20. Each of said work holding fixtures consists of a rotatablework holding member 25 having suitable notches 26 to receive a workpiecesuch as a universal joint spider. With an even number fixtures 11 oncarrier 10 and an uneven number of fixtures 25 on indexer 20, a givenindexer fixture will match with the even-numbered fixtures on carrier 10during one revolution of carrier 10 and with the odd-numbered fixturesduring the next revolution of carrier 10.

As the carrier Work fixtures 11 pass through the transfer point, thefixture carrying a half-finished workpiece will release the workpiece tothe indexer. The next carrier work fixture which should be empty willreceive an indexed, half-finished workpiece from the indexer.

Work holding member 25 has an integral stub shaft portion 27 journaledOn a support member 28. A reduced portion 29 of stub shaft portion 27extends beyond the support member 28 and has an index wheel 30 attachedthereto by means of pin 31.

A ball is urged by spring 36 into engagemnet with a depression 37 in theunderside of work holding member 25 to locate said work holding member25 to properly align a workpiece in the indexed position for transferback into the grinding fixtures .11 of work carrier 10. A sphericalmember 40 is supported on bracket 41 in position to engage the indexwheel 30 and rotate the work holding fixture to position the ungroundsurfaces of workpieces 13 for grinding as it passes by said sphericalmember 40.

Work carrier 10 and index member 20 are rotated at such a rate that thenotches 26 in the work holding members 25 coincide with the notches 12on the work holding fixtures 11 in work carrier 10 at the point oftransfer from carrier 10 to indexer 20 and vice-versa.

The means for transferring a workpiece from a work holding fixture 1 1in work carrier 10 to a work holding member in index member 20 consistsof axially spaced members having central finger-like portions 51 forengaging each of a pair of axially spaced journals on workpiece 13. Oneither side of fingers 51 and in spaced relation thereto are guideportions 54 and 55.

Member 50 is pivotally mounted at 5-2 on a pair of spaced supportmembers 56 at the left and 57 at the right and is urged in a clockwisedirection by means of spring 53. Member 50 is positioned on said supportmembers 56 and 57 at a point above the transfer point. In this position,FIG. 4, fingers 51 are held to the left of the workpiece in the carrierwork holding fixture 11. As the work carrier 10 and index member 20 moveupwardly, fingers 51 and guides remove the workpiece out of carrier workholding fixture 11 and into indexer work holding member 25. As the workholding member 25 and workpiece 13 approach the upper end of member 50,said member 50 is urged in a counter-clockwise direction by workpiece13, and the lower portion of fingers 51 are positioned to the right ofworkpiece 13 in the next work holding member 25 in index member 20.

As the work carrier 10 and index member 20 rotate together, workpiece 13rides along the left hand side'of fingers 51 between said fingers 51 andguides 54, and as another workpiece 13 moves from under the upper end Asthe indexer work fixture 25 carrying a workpiece 13, passes the end offingers 50, the index wheel SO -attached to indexer work fixture 25 isengaged by spherical member 40 and rotated through an angle sufficientto place the next two parallel surfaces of the workpiece in position forgrinding. In this case, the angular movement is 90.

In order to discharge finished workpieces 13 from the work carrier andpermit half-ground workpieces to remain in the work carrier 10 to betransferred to the index member 20, a pair of fingers 60 pivotallymounted in support members 56 and 57 below the transfer point, are urgedin a counter-clockwise direction by means of spring 61. Movement of saidfingers 60 in a counter-clockwise direction is limited by a workpiece 13in one of the work holding fixtures 1 1. When so limited, the lower endsof fingers 60 are held in a position, such that a workpiece 13 in thenext work holding fixture 11 is ejected by fingers 60. When theworkpiece in the first mentioned work holding fixture 11 passes both theupper ends 62 of fingers 60 and releases spring 61, the fingers 60 arethen shifted in a counter-clockwise direction to a position to engagethe right hand side of workpiece 13 and hold it in the work holdingfixture 11 so that it may be transferred to the indexer, indexed andtransferred back into another work holding fixture 11 for the secondgrinding operation.

Means for driving work carrier 10 and index member consists of a motor70 connected through suitable gearing to drive index member 20. Asprocket 71 on index member 20 is connected through a chain 72 and apair of vertically spaced sprockets 78 and 79 between which the chain 72makes a reverse path about sprocket 73 on work carrier 10. The ratiobetween sprocket 71 on index member 20 and sprocket 73 on work carrier10 is such that the work holding members on each member 10 and 20coincide or mate at the point of transfer.

Limit switch LS1 is mounted on bracket 75 in position to engage a seriesof pads 76 angularly spaced about one side of work carrier 10. Limitswitch LS1 is connected in series with a gauge contact 77. The positionof limit switch LS1 with relation to work carrier 10 and gauge contact77 is such that when workpiece 13 is passing through the gauge, limitswitch LS1 is actuated by one of the pads 76 and the gauge circuit isoperative only at this time. Under certain circumstances, it may bedesirable to prevent the rotation of the work carrier 10 or index member'20.

As indicated above, each workpiece must be carried through the grindingzone by the carrier, removed from the carrier, indexed and returned tothe carrier to make a second pass through the grinding zone. This meansthat when a workpiece on the carrier reaches the discharge point, itmust either be removed from the carrier or retained in the carrier to belater removed by the indexer.

The angular position of the fingers which remove or retain theworkpieces in the carrier as well as the fingers which guide theworkpieces from the carrier to the indexer and from the indexer to thecarrier, is determined by the presence or absence of a workpiece in thecarrier or indexer.

Since the workpieces in the carrier at the discharge point arealternately finished or half-finished, and since the finished piece mustbe discharged, the operation of the finger 60 and also finger 50 isalternately determined by an empty work holder or a work holder having aworkpiece in it. The empty carrier work holder then receives ahalf-ground and indexed workpiece from the indexer. The empty index workholder permits finger 60 to be held by its spring in its clockwiseposition so that a workpiece will be transferred from the next holder onthe carrier to the next holder on the indexer. Thus, the operation ofthe carrier and indexer is dependent on workpieces. If a carrier workholder were allowed to the proper disposition of the finished andhalf-finished pass through the discharge point empty, it would causefingers 60 and 50 to function in such a manner as to remove half-groundworkpieces and cause the finished workpieces to again be subjected tothe grinding operation.

Limit switch LS2 is mounted on bracket 75 for operation in a horizontalplane. The arm of limit switch LS2 rests on projection 81 on a workengaging shoe 82 which is pivotally mounted at 83 on bracket 75 and heldagainst workpiece 13 by spring 84. So long as there is a workpiece ineach work holding fixture, shoe 82 will be held in position to closelimit switch LS2. If an empty work holding fixture 11 attempts to passshoe 82, spring 84 will urge shoe 82 to a position to release limitswitch LS2 and open the circuit to motor 70.

In the cover is mounted a limit switch LS3, to which is hinged a feelermember 101 which rests upon a ledge inside cover 100. LS3 is in serieswith LS2. Peeler member 101 includes an adjustable bar having a pair offingers 102 thereon, spaced to coincide with the journals on a workpiece13. If workpiece 13 is not solidly positioned in the Work holdingfixture 1 1, it will engage fingers 10 2 and actuate limit switch LS3 toopen the circuit to motor 70. Switches LS2 and LS3 are in series so thatboth must be closed to keep motor 70 in operation.

We claim:

1. In a disc grinder for grinding pairs of parallel sides or ends ofworkpieces, rotatable abrasive discs having opposed operative surfaces,a rotatable work carrier for carrying workpieces between said operativesurfaces, peripherally spaced work holders on said work carrier, meansfor repositioning workpieces in said work carrier to grind a second pairof parallel sides on each workpiece comprising a rotatable indexermounted in peripherally opposed relation to said work carrier and havingperipherally spaced work holders thereon, means for rotating said workcarrier and said indexer in predetermined timed relation so that thework holders on said carrier and said indexer are in matching relationat the point at which they approach most closely, selective means forremoving finished workpieces from said work carrier and for retainingpartly finished workpieces in said work carrier comprising a fingerpivotally mounted in fixed relation to said carrier and said indexer andnormally held yieldingly in position to retain a workpiece in said workholder, said finger having an upper portion operable in response tomovement of a workpiece in said indexer to shift the lower end of saidfinger to a position to remove a finished workpiece from said workcarrier in response to the movement of said partly finished workpiece insaid indexer.

2. In a disc grinder for grinding pairs of parallel sides or ends ofworkpieces, rotatable abrasive discs having opposed operative surfaces,a rotatable work carrier for carrying workpieces between said operativesurfaces, an even number of peripherally spaced work holders on saidwork carrier, means for repositioning workpieces in said work carrier togrind a second pair of parallel sides on each workpiece comprising anindexer mounted in peripherally opposed relation to said work carrierand having an un-even number of peripherally spaced work holdersthereon, means for rotating said work carrier and said indexer inpredetermined timed relation, means for transferring workpieces fromsaid work carrier to said indexer including a pivoted finger normallyresiliently urged in a direction toward a position to hold workpieces insaid carrier work holder after the first pair of parallel surfaces havebeen ground, said finger being shaped so that when a workpiece engagesthe upper end thereof, said finger will be rotated in a clockwisedirection to a position on the opposite side of the next workpiece sothat the movement of said first workpiece along said next finger will beeffective to remove said workpiece from said work carrier to saidindexer.

3. In a disc grinder for grinding pairs of parallel sides or ends of aworkpiece, rotatable abrasive discs having opposed operative surfaces, awork carrier rotatably mounted for carrying workpieces between saidoperative surfaces, peripherally spaced work holders on said workcarrier, means for repositioning workpieces in said work carrier togrind a second pair of parallel sides on the workpiece comprising anindexer rotatably mounted in peripherally opposed relation to said workcarrier and having peripherally spaced work holders rotatably mountedthereon, means for rotating said work carrier and said indexer inpredetermined timed relation, means operable in response to the rotationof said work carrier and said indexer for transferring workpieces fromsaid work carrier to said indexer, means responsive to rotation of saidindexer to turn a work holder to place a second pair of parallel sidesin position to be ground, and means for thereafter transferring saidworkpieces back to said work carrier.

4. In a disc grinder for grinding pairs of parallel sides or ends of aworkpiece, rotatable abrasive discs having opposed operative surfaces, awork carrier for carrying workpieces between said operative surfaces,peripherally spaced work holders on said work carrier, means forrepositioning workpieces in said work carrier to grind a second pair ofparallel sides on the workpiece comprising an indexer mounted inperipherally opposed relation to said work carrier and havingperipherally spaced work holders thereon, means for rotating said workcarrier and said indexer in predetermined timed relation, means fortransferring workpieces from said work carrier to said indexer includinga finger, and means for resiliently holding said finger in position toretain a workpiece in said work carrier after it has been ground.

5. In a disc grinder for grinding pairs of parallel faces of aworkpiece, rotatable abrasive discs having opposed operative surfaces, arotatable work carrier for carrying workpieces between said operativesurfaces, peripherally spaced work holders on said work carrier, meansfor repositioning workpieces in said work carrier to grind a second pairof parallel sides on each workpiece including a rotatable indexingdevice mounted tangentially of said carrier, work transfer meansintermediate the carrier and the indexing device, for transferringworkpieces from said work carrier to said indexing device, means on saidindexing device for turning said workpiece to position the second pairof parallel sides for grinding, means on the transfer means forthereafter transferring said workpiece from said indexing device to saidwork carrier, and means for actuating said work carrier and saidindexing device simultaneously.

6. In a disc grinder for grinding pairs of parallel faces of a rotatableworkpiece, rotatable abrasive discs having opposed, operative surf-aces,a work carrier for carrying workpieces between said operative surfaces,peripherally spaced work holders on said work carrier, means forrepositioning workpieces in said work carrier to grind a second pair ofparallel sides on each workpiece including a rotatable indexing devicemounted tangentially of said carrier, work transfer means intermediatethe carrier and the indexing device, for transferring workpieces fromsaid work carrier to said indexing device, means on said indexing devicefor turning said workpiece to position the second pair of parallel sidesfor grinding comprising a work holder, an indexing wheel on said workholder, and means to engage and rotate said index wheel and said workholder into position opposite the transfer means to replace theworkpiece on the carrier with the unground portions of a workpiece inposition to be ground.

-'7. In a disc grinder for grinding pairs of parallel sides and ends ofworkpieces, having two rotatable abrasive discs with opposed operatingsurfaces, a rotatable work carrier member for carrying workpiecesbetween said discs, means for repositioning workpieces in said workcarrier to grind a second pair of parallel sides on each workpiececomprising a rotatable work indexer member mounted in peripherallyopposed relation to said york carrier on an axis parallel to that of thework carrier, one of said members having an even number of work holdersthereon, the other member having an uneven number of work holders, meansfor rotating said two members at the same peripheral speed, meansassociated with said indexer member for angularly indexing said workholders on the indexer member, and means for transferring alternateworkpieces between said work carrier and said indexer member.

References Cited in the file of this patent UNITED STATES PATENTS Re.24,104 Robbins Dec. 27, 1955 1,923,931 Jones Aug. 22, 1933 1,939,038Bower et a1 Dec. 12, 1933 2,128,186 Jones Aug. 23, 1938 2,404,648Meyerhofl July 23, 1946 2,779,956 Butler et a1. Feb, 5, 1957 2,809,471Jones Oct. 15, 1957

